With this type of conventional art, a pair of right and left mounting frames are disposed on the right and left sides of the tractor body. Each one of the right and left mounting frames is formed of a plate member having a plate thickness along the right/left direction. The mounting frame includes a front mounting portion to be connected to a mounting body for mounting a front implement such as a front loader, a case mounting portion to be connected to a rear axle case of the tractor body and a vertical connecting portion formed rearwardly of the case mounting portion and for connecting a rear implement.
This mounting frame has a flat-plate like shape from the case mounting portion to the vertical connecting portion. And, right and left leg portions of a ROPS (Rollover Protection System) are connected to the rear axle case, independently of the mounting frame (see. e.g. JP2004-114762A).